Global Navigation Satellite System (GNSS) receivers have been incorporated into a multitude of devices, including mobile devices such as mobile phones, wrist watches, and other portable devices. Many small mobile devices are configured to be mounted in a cradle device, or worn by a user, and may make use of GNSS signals and Inertial Navigation Systems (INS) to provide positioning information. Positioning estimates may be calculated by receiving and processing satellite positioning signals. Satellite positioning signals, however, are often blocked and a mobile device may utilize inertial navigation techniques to estimate an incremental position. GNSS receivers also generally require more power, which can be an issue with smaller mobile devices. A mobile device may opt to utilize inertial navigation techniques in an effort to conserve battery power.
Inertial navigation techniques may rely on measurement data from inertial sensors (e.g., accelerometers and gyroscopes). However, errors in the position results generated from the inertial sensors may occur when the relative orientation between the sensors and the object in motion are misaligned. Such a misalignment may cause the position results to become less reliable and the misalignment must be calibrated and compensated. The reliability of the position estimates may be further diminished over time because of increasing drift, inaccurate misalignment calibration, or subsequent changes in the relative alignments between the sensors and the object in motion.